1. Technical Field of the Invention
This invention generally relates to presser assemblies for a blanking operation, and, more particularly, to presser assemblies for supporting blanking scrap such as carton or paper blanking scrap during a blanking operation.
2. Description of Related Art
In the manufacture of cartons and paper products, small sheets of material are typically cut out of larger sheets. These smaller sheets are known as blanks. Blanks can be formed into various shapes, such as, by way of example, boxes. Blanks are formed during a process known as a blanking operation. In a blanking operation, the blanks are cut, but not necessarily removed, from a large sheet of carton, paper, paperboard, or cardboard material. After the blanks are cut, the sheet is positioned over a frame for support. The frame typically includes large openings that correspond in size and in position to the blanks previously cut. Below the frame is a mechanism for stacking the blanks.
To hold the scrap material during a die cutting, scoring, creasing, or embossing operation, what is known in the art as a presser assembly is used. The presser assembly can include a member that is biased away from a tool support plate, such as a die rule retaining board. As the tool is lowered, the presser member frictionally engages the sheet of material such that the blanking sheet is secured between the presser member and a counterplate or frame. The tool continues to approach the blanking sheet while the blanking sheet is stabilized by the presser member.
Presser assemblies of the prior art, by virtue of their configuration and size, generally do not offer the possibility of holding relatively small portions of blanking scrap of a blanking sheet. Hence, where relatively small portions of blanking scrap are all that remains of the blanking sheet, there disadvantageously exists the possibility when using presser assemblies of the prior art that such smaller portions of the blanking sheet may not be stabilized or engaged by conventionally sized and designed presser assemblies. Furthermore, because presser assemblies need to be positioned clear of cutting, scoring, creasing, and embossing tools, there is often insufficient space in which to position or mount a conventional presser assembly.
The prior art fails to provide a plunger assembly that offers a simple configuration which is less costly to manufacture and easier to assemble, and which is further easily and efficiently mountable to a support plate, such as a backer board, of a blanking device. In addition, the prior art fails to provide a plunger assembly that offers a configuration and size that can be used to effectively advance, grip, and frictionally engage relatively smaller portions of a blanking sheet and/or blanking scrap during a blanking operation.
It is a purpose of the present invention to solve the above-mentioned problems.
To achieve the above purpose, the present invention provides a plunger assembly for gripping and/or frictionally engaging cut or uncut blanks and/or blanking scrap during a blanking operation. According to an embodiment of the present invention, a plunger assembly is provided that includes: a base member, a pivoting gripper member, and pivoting, connecting legs connecting the base member to the gripping member. The legs include a biasing device to maintain the base member and the pivoting gripper member spaced from each other.
Further details of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.